To drain or not to drain in colorectal anastomosis: a meta-analysis.

BACKGROUND: Currently, many surgeons place a prophylactic drain in the abdominal or pelvic cavity after colorectal anastomosis as a conventional treatment. However, some trials have demonstrated that this procedure may not be beneficial to the patients. OBJECTIVE: To determine whether prophylactic placement of a drain in colorectal anastomosis can reduce postoperative complications. METHODS: We systematically searched all the electronic databases for randomized controlled trials (RCTs) that compared routine use of drainage to non-drainage regimes after colorectal anastomosis, using the terms "colorectal" or "colon/colonic" or "rectum/rectal" and "anastomo*" and "drain or drainage." Reference lists of relevant articles, conference proceedings, and ongoing trial databases were also screened. Primary outcome measures were clinical and radiological anastomotic leakage. Secondary outcome measures included mortality, wound infection, re-operation, and respiratory complications. We assessed the eligible studies for risk of bias using the Cochrane Risk of Bias Tool. Two authors independently extracted data. RESULTS: Eleven RCTs were included (1803 patients in total, 939 patients in the drain group and 864 patients in the no drain group). Meta-analysis showed that there was no statistically significant differences between the drain group and the no drain group in (1) overall anastomotic leakage (relative risk (RR) = 1.14, 95 % confidence interval (CI) 0.80-1.62, P = 0.47), (2) clinical anastomotic leakage (RR = 1.39, 95 % CI 0.80-2.39, P = 0.24), (3) radiologic anastomotic leakage (RR = 0.92, 95 % CI 0.56-1.51, P = 0.74), (4) mortality (RR = 0.94, 95 % CI 0.57-1.55, P = 0.81), (5) wound infection (RR = 1.19, 95 % CI 0.84-1.69, P = 0.34), (6) re-operation (RR = 1.18, 95 % CI 0.75-1.85, P = 0.47), and (7) respiratory complications (RR = 0.82, 95 % CI 0.55-1.23, P = 0.34). CONCLUSIONS: Routine use of prophylactic drainage in colorectal anastomosis does not benefit in decreasing postoperative complications.

Hyperthermia combined with 5-fluorouracil promoted apoptosis and enhanced thermotolerance in human gastric cancer cell line SGC-7901.

This study was designed to investigate the proliferation inhibition and apoptosis-promoting effect under hyperthermia and chemotherapy treatment, at cellular level. Human gastric cancer cell line SGC-7901 was cultivated with 5-fluorouracil at different temperatures. Cell proliferation and apoptosis were determined, and expression of Bcl-2 and HSP70 was measured at different treatments. Cell survival rates and inhibition rates in chemotherapy group, thermotherapy group, and thermo-chemotherapy group were drastically lower than the control group (P<0.05). For tumor cells in the thermo-chemotherapy group, survival rates and inhibition rates at three different temperatures were all significantly lower than those in chemotherapy group and thermotherapy group (P<0.05). 5-Fluorouracil induced apoptosis of SGC-7901 cells with a strong temperature dependence, which increased gradually with increase in temperature. At 37°C and 43°C there were significant differences between the thermotherapy group and chemotherapy group and between the thermo-chemotherapy group and thermotherapy group (P<0.01). The expression of Bcl-2 was downregulated and HSP70 was upregulated, with increase in temperature in all groups. Cell apoptosis was not significant at 46°C (P>0.05), which was probably due to thermotolerance caused by HSP70 accumulation. These results suggested that hyperthermia combined with 5-fluorouracil had a synergistic effect in promoting apoptosis and enhancing thermotolerance in gastric cancer cell line SGC-7901.

The role of microRNA-1274a in the tumorigenesis of gastric cancer: accelerating cancer cell proliferation and migration via directly targeting FOXO4.

MicroRNAs (miRNAs) are a series of 18-25 nucleotides length non-coding RNAs, which play critical roles in tumorigenesis. Previous study has shown that microRNA-1274a (miR-1274a) is upregulated in human gastric cancer. However, its role in gastric cancer progression remains poorly understood. Therefore, the current study was aimed to examine the effect of miR-1274a on gastric cancer cells. We found that miR-1274a was overexpressed in gastric cancer tissues or gastric cancer cells including HGC27, MGC803, AGS, and SGC-7901 by qRT-PCR analysis. Transfection of miR-1274a markedly promoted gastric cancer cells proliferation and migration as well as induced epithelial-mesenchymal transition (EMT) of cancer cells. Our further examination identified FOXO4 as a target of miR-1274a, which did not influence FOXO4 mRNA expression but significantly inhibited FOXO4 protein expression. Moreover, miR-1274a overexpression activated PI3K/Akt signaling and upregulated cyclin D1, MMP-2 and MMP-9 expressions. With tumor xenografts in mice models, we also showed that miR-1274a promoted tumorigenesis of gastric cancer in vivo. In all, our study demonstrated that miR-1274a prompted gastric cancer cells growth and migration through dampening FOXO4 expression thus provided a potential target for human gastric cancer therapy.

Combination of the FGFR4 inhibitor PD173074 and 5-fluorouracil reduces proliferation and promotes apoptosis in gastric cancer.

Our previous findings revealed that FGFR4 may be a novel therapeutic target for gastric cancer. The aim of the present study was to explore the effects of a combination of PD173074 (PD) and 5-fluorouracil (5-Fu) on the biological behavior of gastric cancer cell lines and the relevant mechanisms involved. MKN45, a gastric cancer cell line, was treated with each single agent alone or a combination of FGF19, PD and 5-Fu. Then, a series of functional assays were performed using CCK-8 assay and flow cytometry. Western blot analysis was used to determine the expression of signaling pathway and downstream-related molecules in the MKN45 cells following the different treatments. As the concentration of PD and 5-Fu increased, the cell viability gradually decreased; the viability of the combination group was less than the viability following single administration. Western blot analysis showed that FGFR4 expression was weak in the 5-Fu-treated groups when compared with the control. PD markedly increased the apoptosis rate of MKN45 cells when compared to the control; the apoptosis rate in the cells treated with the combination of PD and 5-Fu was higher than that in the cells following single treatment. Furthermore, PD reduced the expression of p-ERK and Bcl-xl and increased caspase-3 expression. Inhibition of the activity of FGFR4 may be the main mechanisms of PD effect while 5-Fu reduced FGFR4 expression. Furthermore, the effects of the combination of 5-Fu and PD in inhibiting proliferation, increasing apoptosis and arresting cell cycle were superior to these effects following the single agent treatments, suggesting that the two drugs applied in combination may contribute to the effective treatment of gastric cancer.

The correlations between the expression of FGFR4 protein and clinicopathological parameters as well as prognosis of gastric cancer patients.

BACKGROUND: Fibroblast growth factor receptor 4 (FGFR4) was seldom investigated in gastric cancer (GC). The purpose of the study was to elucidate the expression of FGFR4 protein in GC and related clinical significance. METHODS: Ninety-four paraffin-embedded tumor specimens were obtained from Cancer Hospital, Fudan University. The expression of FGFR4 as well as p53, p21, EGFR, neu, c-myc, and PCNA were detected by immunohistochemical method. Then, correlation analysis and survival analysis were performed. RESULTS: The expression rate of FGFR4 protein in GC tissues and normal stomach tissues was 93.6% and 30.8%, respectively (P = 0.000). The expression of FGFR4 was positively correlated with the expression of p21, neu and PCNA (P-value was 0.009, 0.012, and 0.018, respectively). Subgroup analysis showed that compared to low expression group, the prognosis of patients with III/IV stage and negative expression of p21 in high expression group of FGFR4 were worse (P = 0.048, 0.041, respectively). Multivariate analysis showed that TNM stage was the independent prognostic factor in high expression group (HR, 11.593; 95% CI, 3.532-18.058; P = 0.000). CONCLUSIONS: High expression of FGFR4 protein, accelerating the progression of advanced GC, might be associated with a poor prognosis in patients with advanced FC.

Fibroblast growth factor receptor 4 regulates proliferation and antiapoptosis during gastric cancer progression.

BACKGROUND: Fibroblast growth factor receptor 4 (FGFR4) belongs to the tyrosine kinase receptor family. Little is known about the effect of FGFR4 on gastric cancer (GC). Therefore, the objective of the current study was to elucidate the role of FGFR4 in the tumorigenesis and progression of GC. METHODS: FGFR4 and some common prognosis markers, including p53, neu, and proliferating cell nuclear antigen (PCNA), were detected in 71 tissue samples from patients with GC using immunohistochemical analysis. In addition, a series of functional assays were carried out using small interfering RNA (siRNA) and included proliferation assays, clone assays, and apoptosis detection. RESULTS: Cytoplasmic FGFR4 expression in GC tissues was negative (7% of samples), low (14.1% of samples), intermediate (40.8%), and high (38% of samples). FGFR4 expression was associated with lymph node status and with PCNA and neu expression (P < .05). The 5-year relative survival rate was 61.5% in patients who had GC with low FGFR4 expression but was only 42% in patients who had high FGFR4 expression (P = .058). A subgroup analysis of the patients who had high FGFR4 expression revealed that those with stage III and IV disease had a worse prognosis (P = .044). Moreover, knockdown of FGFR4 expression led to decreased proliferation and an increased rate of apoptosis in the MKN45 and SGC7901 GC cell lines (P < .05). Western blot analysis demonstrated that the expression of caspase 3 increased, whereas the expression of extra-large B-cell lymphoma (Bcl-xL) decreased in MKN45 and SGC7901 cells after FGFR4-siRNA transfection. CONCLUSIONS: FGFR4 expression in GC tissue was extremely high. The current results indicated that FGFR4 may contribute to the progression of GC by regulating proliferation and antiapoptosis, indicating that FGFR4 may be a potential, novel drug target against GC.

Sox17 regulates proliferation and cell cycle during gastric cancer progression.

Sox17, a transcription factor, was considered as an antagonist to inhibit canonical Wnt/ß-catenin signaling in several malignant tumors. Extremely little is known about Sox17 in gastric cancer. Therefore, the aim of this study was to elucidate the vital role of Sox17 in the tumorigenesis and progression of gastric cancer. Real time PCR was used to detect the expression of Sox17 in gastric cancer tissue. Furthermore, a series of function assays, utilizing small interfering RNA (siRNA)-mediated knockdown of Sox17 expression in MKN45 gastric cancer cells, have been performed in this study, including proliferation assay, clonogenic assay, cell-cycle evaluation, apoptosis detection as well as western blot assay. Sox17 expression were low in gastric cancer tissues as compared to normal tissue (P=0.013). Knockdown of Sox17 by Sox17-siRNA markedly enhanced the proliferation ability of MKN45 cells when compared with negative siRNA-infected cells and mock group (P<0.05). Down-regulation of Sox17 contributed to increasing cloning efficiency and activating cell cycle of MKN45 cells (P<0.05). However, there was no significantly statistical difference in terms of apoptosis rate between Sox17-siRNA group and Negative or mock group. Western blot assay revealed that the expression of CyclinD1 observably increased while p27(Kip1) expression remarkably decreased in MKN45 cells with Sox17-siRNA transfection. Furthermore, apoptosis-related molecules, Caspase3 and Bcl-xl, have no dramatically discrepant expression when knockdown of Sox17 in MKN45 cells. Sox17 prominently contributes to gastric cancer progression through regulating proliferation and cell cycle, indicating a novel diagnosis and prognosis biomarker as well as a potential therapeutic target in gastric cancer.

Prognostic analysis of familial gastric cancer in Chinese population.

BACKGROUND: The aim of this study was firstly to elucidate the prognosis of familial gastric cancer (FGC) in Chinese population. METHODS: A total of 162 patients were recruited, including 81 patients with FGC and 81 patients with sporadic gastric cancer (SGC), who underwent gastrectomy between 1996 and 2007. Paraffin-embedded tumor specimens were obtained from tissue bank of Cancer Hospital, Fudan University. The expression of epidermal growth factor receptor (EGFR), P53, C-myc, and proliferating cell nuclear antigen (PCNA) were detected by immunohistochemical method. RESULTS: There were significant differences in tumor size, vessel invasion, EGFR, and P53 expression between FGC and SGC patients. The 5-year survival rates were 48% and 57% in FGC and SGC patients, respectively (P = 0.033). Subgroup analysis showed that the 5-year survival rates were worse in FGC patients with nerve invasion, high PCNA expression, negative expression of EGFR, and positive expression of P53 than those in SGC group. Multivariate analysis showed that AJCC stage, tumor size, and nerve invasion were independent prognostic factors in all patients. Furthermore, AJCC stage and P53 expression dramatically affected the prognosis of FGC patients. CONCLUSIONS: The prognosis of FGC patients might be worse than those of SGC patients. AJCC stage and P53 expression are independent prognostic factors in FGC patients.

[Clinicopathological and prognostic analysis of 23 poorly differentiated neuroendocrine carcinomas of the stomach].

OBJECTIVE: To evaluate the clinicopathological characteristics and prognosis of poorly differentiated neuroendocrine carcinoma of the stomach. METHODS: Twenty-three poorly differentiated neuroendocrine carcinomas of the stomach were treated in the Department of Abdominal Surgery at the Cancer Hospital, Fudan University between January 1996 and December 2007. Clinicopathological characteristics and survival data were analyzed. RESULTS: Poorly differentiated neuroendocrine carcinomas of the stomach accounted for 0.52% of all the gastric carcinomas. The tumor occurred more often in males (18 of 23), older patients (mean age of 62 years), upper third of the stomach (16 of 24,one patient had more than one lesion) with large size (mean diameter of 6.8 cm). TNM stages were as follows: stage II in 3 patients, stage III in 12, and stage IIII in 8. Thirteen patients underwent curative resection, while 8 underwent palliative resection and 2 others underwent exploratory laparotomy with biopsy. Of the 21 surgical resection specimens, vascular invasion was found in 18 patients (85.7%), perineural invasion in 16 patients (76.2%), and regional lymph node metastasis in 17 patients (81.0%). Follow up time ranged from 3 to 63 months. Mean overall survival time was 17.7 months. The 1-year, 2-year, and 5-year survival rates were 47.8%, 19.1%, and 4.3%, respectively. Statistically significant differences in survival curves were observed which were related to tumor staging and surgery type, but not related to gender, age, tumor location, or diameter. CONCLUSIONS: Poorly differentiated neuroendocrine carcinomas of the stomach are rare and with poor prognosis. Tumor stage and surgical type have potential impact on survival.

[Oncogenic signaling mechanisms in imatinib-resistant gastrointestinal stromal tumor].

OBJECTIVE: To characterize oncogenic KIT signaling mechanisms in gastrointestinal stromal tumor(GIST), and to determine which signaling pathway might be of potential relevance to imatinib acquired resistance. METHODS: The mutations of KIT and PDGFRa gene were evaluated and KIT downstream signaling profiles were evaluated in 8 specimen from 5 GIST patients who were evaluated treated between 2003 and 2008 in our hospital. Biochemical inhibition of the expression of related proteins in Ras/Raf/MAPK and PI3-K/AKT pathways, such as KIT, mitogen-activated protein kinase(MAPK),mammalian target of rapamycin(MTOR), AKT, Proliferating cell nuclear antigen (PCNA) and BCL-2, were determined by Western blotting for protein activation. RESULTS: Three cases who showed response to imatinib carried primary mutations in KIT gene, with 2 cases possessing mutation in exon 11, 1 case in exon 13. One case with imatinib-resistance developed KIT secondary mutation, but all the cases had no PDGFRa mutation. p-KIT and p-AKT expressions were higher in the samples of imatinib-resistant GIST than those of imatinib-responsive GIST. Total KIT, MAPK, p-MAPK, p-MTOR expressions were strong and comparable in all varied GISTs, which had no significant difference between imatinib-resistant and imatinib-responsive samples. PCNA and BCL-2 expression varied in samples of different therapy cycles and different location. CONCLUSIONS: Ras/Raf/MAPK and PI3-K/AKT/MTOR pathways are essential to GIST pathogenesis. The KIT secondary mutation and PI3-K/AKT/MTOR pathway are particularly relevant for therapeutic targeting in imatinib-resistant GIST.

[Synchronous or metachronous primary cancers of other organs in 74 patients with gastric cancer].

OBJECTIVE: To study the incidence, clinicopathological characteristics, diagnosis, treatment, and prognosis of synchronous or metachronous primary cancers in patients with gastric cancer. METHODS: Clinical data of 4426 patients with gastric cancer in our hospital from 1996 to 2007 were reviewed. RESULTS: Seventy-four (1.7%) patients had synchronous or metachronous primary cancer of other organ, of whom 10 were synchronous and 64 were metachronous. Colorectal cancer was the most common type of primary cancer in other organs (43.8%), followed by breast cancer (16.3%). The mean time interval between gastric cancer and metachronous primary cancer was 82.2 (3-354) months. The mean age at the diagnosis of gastric cancer was 61.2 (33-84) years. The 5-year overall survival rate was 42.3%. The 5-year survival rates in patients with synchronous cancer, pre-metachronous cancer or post-metachronous cancer were 15.2%, 42.9% and 51.3%, respectively. Causes of death were primary cancers of other organ in 11 patients, gastric cancer in 24, and renal failure in 1 patient. CONCLUSIONS: Primary cancer of other organ should be considered in the management of gastric cancer. Aggressive treatment should be used for the second primary cancer. Gastric cancer is the main cause of death in these patients.

Molecular mechanisms of secondary imatinib resistance in patients with gastrointestinal stromal tumors.

AIMS AND BACKGROUND: Most gastrointestinal stromal tumor (GIST) patients respond to KIT inhibition therapy of imatinib, but eventually become resistant with a median time to progression of 2 years. The mechanism of acquired resistance to imatinib and oncogenic KIT signal transduction in GISTs has not been well defined. We sought to investigate the spectrum of molecular and genomic changes in imatinib-resistant GIST patients. METHODS: KIT and PDGFRA mutations were evaluated in 48 samples obtained from 32 GIST patients who underwent surgery after imatinib treatment. KIT downstream signaling profiles were also investigated in eight specimens of five patients who were clinically responsive or resistant to imatinib therapy. Biochemical inhibition of KIT, mitogen-activated protein kinase (MAPK), mammalian target of rapamycin (MTOR), AKT, proliferating cell nuclear antigen (PCNA) and BCL-2 were determined by western blotting for protein activation. RESULTS: In all 32 GIST patients, activating mutations in the KIT gene were seen in 26 (81.3%) patients, PDGFRA gene mutations were seen in 2 (6.2%) patients and no primary mutations were found in 4 (12.5%) patients. Secondary KIT mutations were identified in 11/14 (78.6%) imatinib-acquired-resistance patients, with nine patients in KIT gene exon17, and the other two in exon 13. The expressions of p-KIT, p-AKT, PCNA and BCL-2 were higher in the samples of imatinib-resistant GISTs than those of imatinib-responsive ones. P-KIT, p-AKT expressions were higher in imatinib acquired-resistance GISTs with secondary KIT mutations than imatinib-responsive ones with primary mutation. Total KIT, MAPK, p-MAPK, p-MTOR expressions were comparable in all varied GISTs. CONCLUSIONS: Novel additional mutations of KIT gene exon 13 or exon 17 indicate the likely mechanism of secondary resistance to imatinib. The PI3-K/AKT pathway might be more relevant than MEK/MAPK for therapeutic targeting in imatinib-resistant GIST patients with secondary mutation.

Study on the different expression of molecular markers between cardiac cancer and distal gastric cancer and their correlations with clinicopathological features.

BACKGROUND AND AIM: Currently, few studies have reported the different expression of molecular markers between distal gastric cancer and cardiac cancer. Here, we sought to make an investigation about it by a retrospective analysis. METHODS: The expression of 8 proteins, including epidermal growth factor receptor, glutathione S-transferase pi (GST-pi), cyclin D1, Neu/Her-2, C-myc, p53, p27 and p21, were evaluated in 110 cases with cardiac cancer and 101 cases with distal gastric cancer who underwent curative surgery at the Cancer Hospital, Fudan University, in 2005 by immunohistochemistry method. RESULTS: The TNM stage, differentiation grade, invasion depth and lymph node metastasis were significantly different between cardiac cancer and distal gastric cancer. p21 (p = 0.034), Neu (p = 0.017), and GST-pi (p = 0.003) were expressed in relatively higher levels in cardiac cancer than in distal gastric cancer. Furthermore, the clinical pathological parameters were significantly correlated with the expression of molecules mentioned above. CONCLUSION: Different molecular mechanisms may be involved in the tumorigenesis and development of cardiac cancer and distal gastric cancer.

[Differential expression of immunohistochemical markers between cardiac carcinoma and carcinoma in antrum of stomach and correlation thereof with clinicopathological factors].

OBJECTIVE: To study the differences in expression of several common immunohistochemical markers: epidermal growth factor receptor (EGFR), topoisomerase II (TOPOII), glutathione S-transferase pi (GST-pi), proliferation cell nuclear antigen ( PCNA), Her-2/Neu, P27, P21, and P53, between cardiac carcinoma and carcinoma in antrum of stomach and the correlation thereof with clinicopathological factors. METHODS: 211 paraffin-embedded tissue samples of gastric cancer were randomly chosen from the patients of cardium and stomach operated in 2005, including 110 cases of cardiac carcinoma and 101 cases of carcinoma in antrum of stomach. Immunohistochemical Envision two step method was used to detect the expression of the above mentioned markers. RESULTS: Compared to the cardiac carcinoma, the carcinoma in antrum of stomach showed higher rate of clinicopathological staging was significantly higher, degree of differentiation lower, invasion deeper, and degree of lymph node metastasis higher (all P < 0.05). The expression rates of P21, Her-2/Neu, and GST-pi of the cardiac carcinoma group were 80.0% (88/110), 30.9% (34/110), and 92.7% (76/82) respectively, all significantly higher than those of the carcinoma in antrum of stomach group [67.0% (65/97), 16.7% (16/96), and 74.5% (41/55) respectively, P = 0.034, 0.017, and 0.003 respectively]. In the cardiac carcinoma, P21 expression was positively correlated with the expression of P27 and EGFR, the P27 expression was positively correlated with the expression of EGFR and TOPOII, and the GST-pi expression was positively correlated with the TOPOII expression (r = 0.255, P = 0.021). In the antrum of stomach carcinoma, GST-pi expression was positively correlated with the expression of EGFR, TOPOII, and Her-2/Neu, however, it was negatively correlated with the expression of PCNA, and the P27 expression was positively correlated with the P53 expression (r = 0.275, P = 0.042). CONCLUSION: Different molecular mechanisms may lead to the tumorigenesis and development of stomach carcinoma at different sites.

[Surgical treatment for patients with advanced gastrointestinal stromal tumor after targeted therapy].

OBJECTIVE: To explore the role of surgery and its long-term outcome in patients with advanced gastrointestinal stromal tumor(GIST) treated with imatinib preoperatively. METHODS: Thirteen patients receiving imatinib therapy preoperatively, were retrospectively assessed for completeness of surgical resection and for disease-free and overall survival after resection. RESULTS: Thirteen patients, including 3 patients with locally advanced primary GIST and 10 patients with recurrent or metastatic GIST, underwent surgery after preoperative treatment with imatinib. Complete resections were accomplished in 4 of the 5 responsive disease(RD) patients, and in 1 of the 8 progression disease(PD) patients (38.5%). The progression-free survival(PFS) time for patients with RD and PD were 24.8 months and 2.8 months respectively. The difference of PFS between patients with RD and those with PD was significant(P<0.01). Median overall survival(OS) was not reached in both patients with RD and PD. The difference of OS between patients with RD and those with PD was not significant(P>0.05). CONCLUSION: Surgical intervention following imatinib is feasible and can be considered for patients with advanced GIST responsive to imatinib.